The goal of this project is to develop an array of 10-4cm2 electrodes for use with a new instrumental method for tissue culture. The method, referred to as ECIS (electric cell-substrate impedance sensor), is a non-invasive technique to measure several in vitro cell parameters that have previously been difficult to quantify. These include cell motility, adhesion and spreading, morphology and the barrier functions of cell layers. The electronics and software of prototype instrument have been worked out. To be successful, however, a practical method of fabricating electrodes is now required. In Phase I, research will be carried out to test the feasibility of using modern photoresist technology to produce arrays of gold electrodes. Specifically, studies will address (1) modification of photoresist technology for plastic and glass substrates, (2) stability of photoresists in culture media, and (3) compatibility of the system for cell culture. If these studies are successful, a final prototype will be assembled and tested, where computer-addressable electrode pairs will be located on the floor of each well of a standard tissue culture multiwell plate. The long term objective of this work is to develop the ECIS instrument incorporating electrode arrays fabricated using state-of-the art manufacturing procedures. The method will then be a practical and highly sensitive means to monitor cell behavior for both medical and biological research.